I have had my Touch Pad for about a year now and I haven't kept up on the Web OS news. I know HP gave it to the open source community earlier this year and I just found this web
site which may answer my questions.

Will I still be able to get OS updates via the "Check for system updates" icon or will they be made available from another process? Also, how often will updates be made available, if they are? Same with the App Catalog, will apps be updated or new ones made available?

I don't use the device that much and I am a bit dissappointed with it as well. I have had to send it back while under warranty 2x for it not being able to power on. I am thinking about putting Android on it if I can find the time.

How much life does this OS have left? Will parts be available when my TP needs repair or is time to get rid of it?

I'm pretty sure there won't be any more OS updates for the Touchpad. Anything that needs to be fixed will have to be done by the Homebrew community. Catalog apps will continue to get updates, but only if the developer is still working on the app.

As for parts, there will be always someone whose screen shatters and they decide to part up their Touchpad rather than repair, so don't worry about that too much. The times it didn't power on sound like the battery discharged to the point that it could no longer power the charging circuitry. There's a whole thread devoted to fixes for this problem

If you decide to install Android, there's a guide for that, but beware that for some people Android permanently broke the accelerometer or the camera, so proceed with caution, since HP won't be willing to repair those things. Also, some have reported that they still have to boot into webOS to charge the battery.

Sorry if things aren't as sunny as you like... there are however many new developments here in the community, such as the work on LunaCE, an upgraded OS graphical interface layer. It's really good, and there's also the WiFi file sharing utility, and a whole bunch of other stuff that can be found on Preware